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path: root/lib/CodeGen/RegisterClassInfo.cpp
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2011-08-05Detect proper register sub-classes.Jakob Stoklund Olesen
Some instructions require restricted register classes, but most of the time that doesn't affect register allocation. For example, some instructions don't work with the stack pointer, but that is a reserved register anyway. Sometimes it matters, GR32_ABCD only has 4 allocatable registers. For such a proper sub-class, the register allocator should try to enable register class inflation since that makes more registers available for allocation. Make sure only legal super-classes are considered. For example, tGPR is not a proper sub-class in Thumb mode, but in ARM mode it is. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136981 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-16Add TargetRegisterInfo::getRawAllocationOrder().Jakob Stoklund Olesen
This virtual function will replace allocation_order_begin/end as the one to override when implementing custom allocation orders. It is simpler to have one function return an ArrayRef than having two virtual functions computing different ends of the same array. Use getRawAllocationOrder() in place of allocation_order_begin() where it makes sense, but leave some clients that look like they really want the filtered allocation orders from RegisterClassInfo. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133170 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-13Include callee-saved registers in debug output.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132899 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-06Don't try to be clever, just preserve the target's allocation order.Jakob Stoklund Olesen
The order of registers returned by getCalleeSavedRegs is used to lay out the fixed stack slots for CSRs. Some targets like their CSRs used from one end, and some targets want them used from the other end. When computing an allocation order, simply preserve the relative ordering of CSRs that the target specifies in its allocation order. Reordering CSRs would break some targets, ARM in particular. We still place volatiles before the CSRs, providing slightly better results with different calling conventions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132680 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-03Preserve the original ordering when a CSR has multiple aliases.Jakob Stoklund Olesen
Previously, these aliases would be ordered alphabetically. (BH, BL) Print out the computed allocation orders. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132580 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-02Just use a SmallVector.Jakob Stoklund Olesen
I was confused whether new uint8_t[] would zero-initialize the returned array, and it seems that so is gcc-4.0. This should fix the test failures on darwin 9. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132500 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-02Start with a zeroed CSRNum map.Benjamin Kramer
Found by valgrind. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132457 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-02Initialize members to fix problem found by valgrind.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132456 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-02Add a RegisterClassInfo class that lazily caches information aboutJakob Stoklund Olesen
register classes. It provides information for each register class that cannot be determined statically, like: - The number of allocatable registers in a class after filtering out the reserved and invalid registers. - The preferred allocation order with registers that overlap callee-saved registers last. - The last callee-saved register that overlaps a given physical register. This information usually doesn't change between functions, so it is reused for compiling multiple functions when possible. The many possible combinations of reserved and callee saves registers makes it unfeasible to compute this information statically in TableGen. Use RegisterClassInfo to count available registers in various heuristics in SimpleRegisterCoalescing, making the pass run 4% faster. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132450 91177308-0d34-0410-b5e6-96231b3b80d8